German Published Patent Application No. 195 16 481 describes a method of determining a life. A control device for a motor vehicle is described, having a performance data memory in which performance quantities of the vehicle are stored, these quantities being capable of providing information regarding the probability of failure and/or the future reliability of the control device. Essential data on the life history of a control device is stored in the performance data memory to permit a conclusion to be drawn with regard to the reliability of the control device as needed.